The present invention relates to the field of geophysical exploration, and more specifically to adaptation of data to account for position and elevation variations between sources and receivers (generally illustrated in FIG. 1 at source location (101) and receiver location (102)). Geophysical processing involves interpretation of seismic data (100) derived from a seismic source (101) and a seismic receiver (102). Ideally, the source (101) and the receiver (102) should be at a common elevation so that the interpretation of the geologic formations below can be more easily and correctly derived. This is very difficult to achieve in the field. Historically, to simulate this, seismic data processing and interpretation have involved mathematically shifting the source (101) and receiver (102) to a fictitious common elevation plane called a datum (110). However, reflection travel times are often affected by surface and near surface irregularities, including, for example, rapid changes in elevations and earth formations. These irregularities significantly distort the regular hyperbolic or non-hyperbolic moveouts. As such, the shift is ineffective.
Current attempts to remove these distortions involve applying field and residual static corrections to preconditioned data. The drifts of source and receiver location at the datum plane (110) will significantly affect the binning location and the seismic velocities derived from the statically corrected data, because the source and receiver points are only shifted vertically, for example, to a shifted source location (105) and a shifted receiver location (106). These are not the true locations where seismic waves propagate through the datum plane. Using this incorrect geometry to bin the data for processing results in incorrect velocities, even though the seismic gathers can still be flattened for stacking. Applying the incorrectly derived velocities, and possibly incorrect binning locations, results in an incorrect depth image of the subsurface geology.
Further, in the marine environment, when an ocean bottom seismic method is deployed to acquire seismic data, multi-component receivers are deployed on the sea floor (800) and the sources (101) are activated on the sea surface (801). As a result, there is a significant elevation difference between the source (101) and the receivers (102).
There is a great need for a new method and device wherein ray-path corrected source and receiver locations as well as reflection locations are used to obtain the proper geological and lithological information from the seismic data. It is an object of the invention to provide such a method and device.